Pump device for fluid dispenser

ABSTRACT

A pump device for fluid dispensers is provided whose chamber is partitioned into a pressure room and a fluid room. A piston element is engaged inside the pressure room by an actuating rod to push the piston element downward, or by a resilient element beneath the piston element to restore the piston element back to the top. An air valve element at the bottom of the piston element automatically opens or closes the induction of air to the pressure room when the piston element is moved upward or downward. The fluid room is dedicated to the passage of the fluid. A normally closed fluid valve element is provided at the bottom of the fluid room. When the fluid in the container device is pressurized, the fluid pushes open the fluid valve element, flows into the fluid room and then out of the spout of the pump device.

BACKGROUND OF THE INVENTION

(a) Technical Field of the Invention

The present invention generally relates the pump device for fluiddispensers, and more particular to a pump device having partitionedrooms for air and fluid separately.

(b) Description of the Prior Art

Fluid dispensers are commonly found in the household kitchens andbathrooms for holding liquid soaps and detergents, shampoo andconditioners, hand and body lotions, etc. A fluid dispenser usuallycontains a fluid container device and a pump device mounted on top ofthe container device. A conventional pump device is shown in FIG. 1.

As illustrated, the conventional pump device mainly contains a spout A1,a hollow actuating rod A2 attached to the bottom of the spout A1, afastening element A3 for locking the spout A1 when the pump device isnot in use, a closure cap A4 for locking the pump device to thecontainer device (not shown), a hollow chamber A5, a plug element A7attached to the bottom of the actuating rod A2 via an intermediatehollow rod A7 1, a piston element A6 wrapping around the rod A71positioned on top of the plug element A7 having air-tight contact withthe inner wall of the chamber A5, a spring A8, a ball valve A9, and adip tube A10. The operation ofthe pump device is as follows. When thespoutAl is pushed downward, the plug element A7 compresses the spring A8and the piston element A6 drives the air in the chamber A5 downward,forcing the ball valve A9 to block the dip tube A10. When the pressureon the spout A1 is released, the plug element A7 and the piston elementA6 are automatically restored to their original position by the springA8. In the mean time, the air in the chamber A5 is expelled through anumber of ventilation holes A51 configured on the top wall of thechamber A5, thereby vacuuming the space inside the chamber AS. The fluidstored in the container device is therefore sucked into the dip tubeA10, pushes the ball valve A9 aside, and flows into the chamber A5. Whenthe spout A1 is pushed again, the descending of the piston element A6forces the fluid inside the chamber A5 to flow into a through hole A72on the rod A71 between the piston element A6 and the plug element A7,through the actuating rod A2, and then out from the spout A1.

Please note that, when the plug element A7 and the piston element A6 arepushed down, the friction between the piston element A6 and the innerwall of the chamber A5 causes a tiny gap developed between the pistonelement A6 and the plug element A7, thereby exposing the through holeA72. As the ball valve A9 blocks the dip tube A10 under air pressure,only the fluid in the chamber A5 will flow through the through hole A72.On the other hand, when the plug element A7 and the piston element A6are restored as the spring A8 expands, the friction between the pistonelement A6 and the inner wall of the chamber A5 causes the plug elementA7 and the piston element A6 to tightly attach to each other, therebyclosing the through hole A72 and prohibiting the fluid to pass through.In the mean time, the fluid in the container device is sucked into thechamber A5 to make up the amount of fluid dispensed in the previousstroke.

The foregoing conventional pump device has a number of shortcomings.First of all, as the fluid to be dispensed is stored inside the chamber,various components of the pump device are completely immersed in thefluid. These components will quickly deteriorate from the erosion of thefluid, resulting in short operation life. Especially for metalliccomponents such as the spring, they will even engage in chemicalreaction with the fluid, thereby altering the quality and property ofthe fluid.

Secondly, as the fluid has to be pumped into the chamber via narrow diptube and again through the actuating rod, the viscosity of the fluidsignificantly affects the operation of the pump device. For highlyviscous fluid, a user has to exert additional force to obtain anappropriate amount of the fluid in a longer period of time. In otherwords, there is a notable hysteresis phenomenon for both the applicationof force and the response of the pump device.

Thirdly, the same hysteresis problem would also lead to the fluid'scontinuous dripping from the spout after dispensing as the highlyviscous fluid gradually releases its pressure, resulting in userdissatisfaction.

In addition, as the ball valve is the only device blocking the contactof the fluid inside the container device with outside air and the ballvalve can freely move inside the chamber, the fluid's continuousexposure to outside air is inevitable and the conventional pump deviceis therefore not appropriate for highly volatile fluid.

SUMMARY OF THE INVENTION

The primary purpose of the present invention is to provides a novelstructure for the pump device of fluid dispensers to obviate theforegoing shortcomings of prior approaches.

The major characteristic of the present invention is that the chamber ofthe pump device is partitioned into a pressure room and a fluid room. Apiston element is engaged inside the pressure room by an actuating rodto push the piston element downward, or by a resilient element beneaththe piston element to restore the piston element back to the top. An airvalve element at the bottom of the piston element automatically opens orcloses the induction of air to the pressure room when the piston elementis moved upward or downward. As such, air pressure is reliably appliedto the fluid in the container device as the air flows from the chamberinto the container device via an outlet hole therebetween.

The fluid room is dedicated to the passage of the fluid. A normallyclosed fluid valve element is provided at the bottom of the fluid room.When the fluid in the container device is pressurized, the fluid pushesopen the fluid valve element, flows into the fluid room and then out ofthe spout of the pump device.

Compared to the prior arts, the proposed pump device has quite a fewadvantages. Except when the fluid is discharged, the air valve elementand the normally closed fluid valve element seals the container deviceat all time, avoiding volatile fluid to evaporate. Additionally, theseparation of pressure room and the fluid room avoids the erosion anddeterioration of the components as often found in prior arts resultedfrom their direct contact with and immersion within the fluid, therebylengthening the operation life of the pump device considerably. Furthermore, according to the present invention, the air pressure is directlyapplied to the fluid to drive them out of the container device via ashorter passageway, in contrast to the prior approaches which sucks thefluid out through a longer passageway. The present invention istherefore more responsive to the user operation, requires less usereffort, and does not have the dripping problem, even for fluid of highviscosity.

The foregoing object and summary provide only a brief introduction tothe present invention. To fully appreciate these and other objects ofthe present invention as well as the invention itself, all of which willbecome apparent to those skilled in the art, the following detaileddescription of the invention and the claims should be read inconjunction with the accompanying drawings. Throughout the specificationand drawings identical reference numerals refer to identical or similarparts.

Many other advantages and features of the present invention will becomemanifest to those versed in the art upon making reference to thedetailed description and the accompanying sheets of drawings in which apreferred structural embodiment incorporating the principles of thepresent invention is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing a conventional pump device.

FIG. 2 is a perspective view showing the appearance of a pump deviceaccording to an embodiment of the present invention.

FIG. 3 is a perspective exploded view showing the various components ofthe pump device of FIG. 2.

FIG. 4 is a sectional view showing the pump device of FIG. 2.

FIG. 5 contains the top and sectional views showing the fluid valveelement of the pump device of FIG. 2.

FIG. 6 is a sectional view showing another embodiment of the pistonelement of the present invention.

FIG. 7 is a sectional view showing the operation scenario of the pumpdevice of FIG. 2.

FIG. 8 is a sectional view showing an application of the pump device ofFIG. 2.

FIG. 9 is a sectional view showing another application of the pumpdevice of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following descriptions are of exemplary embodiments only, and arenot intended to limit the scope, applicability or configuration of theinvention in any way. Rather, the following description provides aconvenient illustration for implementing exemplary embodiments of theinvention. Various changes to the described embodiments may be made inthe function and arrangement of the elements described without departingfrom the scope of the invention as set forth in the appended claims.

Please refer to FIGS. 2 and 3. As illustrated, a pump device 10according to an embodiment of the present invention mainly contains ahead element 1, an actuating rod 2, a fastening element 3, a pistonelement 4, a resilient element 5, a body member 6, and a fluid valveelement 7. The head element 1 is provided on the top end of theactuating rod 2, and a screw thread 11 is configured around the bottomportion of the head element 1. A corresponding screw thread 31 isconfigured around the inner wall of the ring-shaped fastening element 3so that, when the pump device is not in use, the head element 1 can bescrewed into the fastening element 3. The other end of the actuating rod2 is embedded inside a through hole 41 in the center of the pistonelement 4. The head element 1, the actuating rod 2, and the pistonelement 4 therefore can be engaged in vertical movement together.

The body member 6 has a hollow chamber 62 configured on top of anenclosure cap 63 with a discharging spout 61 extended from the outerwall of the chamber 62. As shown in FIG. 4, the chamber 62 ispartitioned into two separate rooms, a pressure room 621 and a fluidroom 622. The actuating rod 2 penetrates into the pressure room 621 viathe fastening element 3 which seals the piston element 4 from the top.The resilient element 5 is positioned beneath the piston element 4inside the pressure room 621. At the bottom of the through hole 41 ofthe piston element 4, an air valve element 42 is provided that will beopened and closed synchronously with the up and down movement of pistonelement 4, thereby achieving the air induction and exhaust for thepressure room 621.

Please also refer to FIG. 7. An air duct 12 is provided all the way fromthe head element 1 to the bottom of the actuating rod 2, connecting tothe through hole 41 of the piston element 4. When the piston element 4moves downward by pushing the head element 1, the air valve element 42automatically closes the through hole 42 and the air inside the pressureroom 621 is expelled through an outlet hole 6211 configured around thebottom of the pressure room 621. On the other hand, when the pressure onthe head element 1 is released and the piston element 4 is raised upwardby the resilient element 5, the air valve element 42 automatically opensthe through hole 42 and air is drawn into the pressure room 621 via theair duct 12.

The fluid valve element 7 is fixedly positioned at the bottom of thebody member 6, sealing the fluid room 622 from the bottom. As shown inFIG. 5, the fluid valve element 7 has a valve body 71 and a valve lid72. The valve lid 72 is attached to the valve body 71 which has athrough hole 712 in the center surrounded by an indented lid seat 711.By flipping the valve lid 72 toward the valve body 71, the valve lid 72will fit inside the lid seat 711 and seal the through hole 712. As shownin FIG. 8 in which the pump device 10 is tightly installed on acontainer device B by the enclosure cap 63, the inner pressure insidethe container device B is increased when the piston element 4 is pusheddownward and the air in the pressure room 621 is forced into thecontainer device B via the outlet hole 6211. The fluid C inside thecontainer device B, therefore, is forced into the dip tube D, pushesopen the valve lid 72, enters into the fluid room 622, and then flowsout from the discharge spout 61.

Please note that a positioning element 6221 provided inside the fluidroom 622 appropriately presses the folded section of the valve lid 72 sothat the valve lid 72 normally closes the through hole 712 of the fluidvalve element 7 at all times.

As shown in FIG. 9 which is another application of the presentinvention, the fluid C is stored in a storage member B1 inside thecontainer device B.

The lower portion of the storage member B1 (i.e., the portion close tothe bottom of the container device B) is flexible, and the body member 6of the pump device 10 is fixedly joined to the opening of the storagemember B1 on the top. As such, as air is pumped into the containerdevice B, the fluid C in the storage member B1 is ‘squeezed’ out of thestorage member B1 literally.

According to the spirit of the present invention, another embodiment ofthe piston element 4 is shown in FIG. 6, in which the body of the pistonelement 4 is surrounded with a number of washer rings 40 to provideimproved air-tightness as the piston element 4 is moved inside thepressure room 621.

It will be understood that each of the elements described above, or twoor more together may also find a useful application in other types ofmethods differing from the type described above.

While certain novel features of this invention have been shown anddescribed and are pointed out in the annexed claim, it is not intendedto be limited to the details above, since it will be understood thatvarious omissions, modifications, substitutions and changes in the formsand details of the device illustrated and in its operation can be madeby those skilled in the art without departing in any way from the spiritof the present invention.

1. A pump device for use on a container device for dispensing fluidstored in said container device, said pump device comprising anactuating rod, a head element on the top end of said actuating rod, afastening element, a piston element, a resilient element, a body member,and a fluid valve element, wherein said body member has a hollow chamberconfigured on top of an enclosure cap with a discharging spout extendedfrom the outer wall of said chamber; said enclosure cap fastens saidpump device to the opening of said container device; said chamber ispartitioned into a pressure room and a fluid room; said pressure room iscovered by said fastening element through which said actuating rod isextended; said piston element has a central through hole into which theother end of said actuating rod is embedded; said resilient element ishoused inside said pressure room beneath said piston element; an airvalve element is provided at the bottom of said through hole that isopened and closed automatically and synchronously with the up and downmovement of said piston element; said air valve element is opened toallow air to flow into said pressure room via an air duct running fromsaid head element to the bottom of said actuating rod and connecting tosaid through hole of said piston element; said air valve element isclosed when air is driven out from said pressure room into saidcontainer device via an outlet hole; and said fluid valve element isfixedly positioned at the bottom of said body member, covering saidfluid room from the bottom; said fluid valve element has a valve bodyand a valve lid; said valve lid is attached to said valve body which hasa through hole in the center surrounded by an indented lid seat; saidvalve lid is flipped to fit inside said lid seat and seal said throughhole of said fluid valve element; a positioning element provided insidesaid fluid room appropriately presses the folded section of said valvelid so that said valve lid normally closes said through hole of saidfluid valve element.
 2. The pump device according to claim 1, whereincorresponding screw threads are provided at the bottom of said headelement and around the inner wall of said fastening elementrespectively, so as to join said head element and said fastening elementtogether when said pump device is not in use.
 3. The pump deviceaccording to claim 1, wherein fluid of said container device is storedin a storage member inside said container device; said body member ofsaid pump device is fixedly joined to the opening of said storage memberon the top; the lower portion of said storage member is flexible; andthe fluid in said storage member is squeezed out of said storage memberas air is pumped into said container device.
 4. The pump deviceaccording to claim 1, wherein a plurality of washer rings are providedaround the body of said piston element.